Conductive substrates having fine conductive patterns formed on a polymer film or a glass substrate have been used in various fields of applications such as electromagnetic wave-shielding filters, heating wire glass, touch panels, liquid crystal displays and the like, within various fields of application. Meanwhile, in conductive substrates used in display devices or touch panels, in a case in which a line width of a conductive pattern exceeds 3 μm, the conductive pattern may be easily visually discernible from the outside of the substrate due to a difference in reflectance between a conductive pattern layer and the substrate, thereby leading to a deterioration in display quality. Therefore, it is necessary to control the line width of the conductive pattern to be decreased. However, it may be difficult to implement such a fine line width using a manufacturing method of a conductive substrate according to the related art.
More specifically, in order to form a conductive substrate having conductive fine patterns formed therein according to the related art, a method of forming a groove in a glass substrate or a polymer substrate, filling the groove with a conductive material through wet coating or the like, and removing the conductive material coated on portions of the substrate other than that present in the groove using a doctor blade method or the like, a method of filling a groove with metal particles, metallic oxides and the like, and performing compression thereon by applying heat and/or pressure thereto, and the like, may be used.
However, in a wet coating method, a resin containing conductive polymers or conductive particles, or the like may be used as a conductive material. Here, in a case in which conductivity of the resin is significantly low as compared to that of a solid metal and a process rate thereof is increased, a non-filled region in the groove may be easily generated, thereby leading to an increase in a defect rate. In addition, in order to implement a fine line width of 3 μm or less, a conductive material filled in a groove needs to have a significantly fine nano-size, but it may be practically unfeasible to reduce a size of the conductive material in such a manner.
Meanwhile, in the case of a method of compressing metal particles or metal oxide particles by applying heat and/or pressure thereto, pattern deformation may easily occur due to heat and/or pressure to deteriorate the degree of precision, thereby causing limitations in the formation of fine patterns.
Further, in addition to the methods described above, a manufacturing method of a conductive substrate having conductive fine patterns formed therein through a scheme of printing or plating fine patterns using a conductive ink on the substrate, has been suggested. However, in the scheme of performing printing using a conductive ink, in order to realize a fine line width, a droplet size of the conductive ink needs to be decreased to a nano-size level. However, since it may be practically difficult to implement ink droplets sizes in such a manner, the scheme of performing printing using a conductive ink may be inappropriate for forming patterns having a line width of 3 μm or less. In addition, in the case of the plating scheme, since it may be difficult to selectively perform plating only on a groove, a metal layer formed on a region other than the groove needs to be removed through a polishing operation using polishing particles after the plating. However, in this case, since it may be difficult to apply a consecutive process such as a roll-to-roll process thereto, a relatively long manufacturing time may be required, and relatively cumbersome processes may be caused.